1. Field of the Invention
The present invention relates to an ophthalmic photographing apparatus for photographing a fundus and photographing a slit-sectioned anterior segment of an eye to be examined.
2. Description of Related Art
As hand-held fundus cameras, those of mydriasis photographing type and non-mydriasis photographing type are known. In the former, a fundus may be observed under visible illumination light for observation to be photographed in color with a mydriatic administered to an eye. In the latter, a fundus is observed under infrared illumination light for observation to be photographed in color without a mydriatic administered to an eye. Administering a mydriatic places a burden on an eye to be examined, for example, by making the eye so sensitive to light that it is almost blinded in bright light for a while.
It should be noted that, in an ophthalmic examination, it is sometimes necessary to photograph not only a fundus but also a slit-sectioned anterior segment of an eye. However, this requires an examiner to prepare and use a photographing apparatus other than a fundus camera, which is inconvenient for the examiner. In addition, it will be convenient if other parts of an eye than its fundus may be photographed under non-mydriatic conditions.
The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide an ophthalmic photographing apparatus capable of photographing a fundus and a slit-sectioned anterior segment of an eye under non-mydriatic conditions.
To achieve the objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, an ophthalmic photographing apparatus is provided with a light source unit, a hand-held photographing unit, a slit light illumination unit, and a photoconductive tube. Placed in the light source unit are an infrared illumination light source optical system for observation and a visible illumination light source optical system for photographing. Placed in the photographing unit are a first illumination optical system with an illumination lens and an observation/photographing optical system with an objective lens. The photographing unit is separated from the light source unit. Placed in the illumination unit is a second illumination optical system with a slit plate and an illumination lens. The illumination unit is removably attached to the photographing unit. The photoconductive tube connects the light source unit selectively to the photographing unit and the illumination unit, and transmits infrared illumination light for observation and visible illumination light for photographing from the light source unit selectively to the first illumination optical system and the second illumination optical system. The observation/photographing optical system is used to observe and photograph a fundus of an eye to be examined which is illuminated by the infrared illumination light for observation and the visible illumination light for photographing via the first illumination optical system, and to observe and photograph an anterior segment of the eye illuminated by the infrared illumination light for observation and the visible illumination light for photographing via the second illumination optical system.
In another aspect of the present invention, an ophthalmic photographing apparatus is provided with a light source unit, a hand-held photographing unit, a slit light illumination unit, and a photoconductive tube. Placed in the light source unit is a visible illumination light source optical system for photographing. Placed in the photographing unit are an infrared illumination light source optical system for observation, a first illumination optical system with an illumination lens, and an observation/photographing optical system with an objective lens. The photographing unit is separated from the light source unit. Placed in the illumination unit is a second illumination optical system with a slit plate and an illumination lens. The illumination unit is removably attached to the photographing unit. The photoconductive tube connects the light source unit selectively to the photographing unit and the illumination unit, and transmits visible illumination light for photographing from the light source unit selectively to the first illumination optical system and the second illumination optical system. The observation/photographing optical system is used to observe and photograph a fundus of an eye to be examined, which is illuminated by the infrared illumination light for observation and the visible illumination light for photographing via the first illumination optical system. The observation/photographing optical system is also used to observe an anterior segment of the eye illuminated by the infrared illumination light for observation via the first illumination optical system, and to photograph the anterior segment illuminated by the visible illumination light for photographing via the second illumination optical system.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.